That's pretty good Pete and what ever CA was present you look to have handled it quite well. I would love to have ago with some old Pentax 6X7 lenses with my big FLI ProlIne some day.
I used to use a Pentax 6X7 and various lenses back in the mid 80's with some success using film, here's some
Halley's shots
Show us how F5.6 goes
Mike